Abrasive cutoff machine



Nov. 11, 1941. H. e. ROBINSON ABRASIVE CUTOFF MACHINE Original Filed Oct. 24, 1936 6.S heetsSheet l R. v "ms m mm 1 B n O R Q m .V A H N m 1 aw m..

'Nov. 11, 1941.

H. G. ROBINSON [{BRASIYE CUTOFF MACHINE Original Filed Oct. 24, 1936 6 Sheets-Sheet 2 I INVENTOR. HARRY G. ROBINSON. V 4' 19 ATTORNEY ABRASIVE CUTOFF MACHINE Original Filed Oct. 24, 1936 6 Sheets-Sheet I5 INVEN TOR. HARRY 6.. ROBWlfiON Nov. 11, 1941. H. G. RQBINSON 2.262949 ABRAS IVE CUTOFF MACHINE briginal Filed Oct. 24, 1956 e Sheets-Sheet 4 INVENTOR. HARRY G. eoswsorg m ATTORNEY Nov. 11, 1941. H. G. ROBINSON 2,262,049

ABRASIVE CUTOFF MACHINE )ri gina]; Fild Oct. 24, 1936 6 Sh eets-Sheet 6 I2? I25 /24 32 5/ //7 L75 BY R W ATTORNEY I "INVENTOR. HARRY. G ROBlNSON.

pended claims.

- machine being shown Patented Nov. 11, 1941 I Harry G. Robinson, Stratford, Conn.,

assignor to American Chain & Cable Company, Inc.,- New York, N. Y., a corporation of New Continuation of application York Serial No. 107,347,

October 24, 1936. This application January 8, 1938, Serial No. 183,927

11 Claims.

This invention relates to new and useful improvements in method and means of cutting and the present application is a continuation of my application Serial Number 107,347, filed October 24, 1936.

An object of the invention is to provide an improved method and means whereby with a minimum expenditure of power a smooth clean cut may be obtained.

Other objects and advantages will become apparent as the description proceeds. However it is to be understood that the invention is not lim ited to the details described herein and shown in the accompanying drawings but includes all such variations and modifications as fall within the scope of the ap spirit of the invention and the 'In the drawings:

Fig. 1 is a front elevational view of a machine constructed in accordance with the invention;

Fig. 2 is a side elevational view thereof, the as viewed from the left in 1;

Fig. 3 is a rear elevational view of the machine: r

Fig. 4 is a sideelevational view thereof, the view being taken looking from the-right in Fig. 1;

Fig. 5 is an elevational view on an enlarged scale and showing'a control employed;

Fig. 6 is a similar view showing a releasing le ver of the control:

Fig. 7 is an enlarged-detail view showing a crank means employed;

Fig.8 is an enlarged horizontal sectional view through the cut-off housing, the view being taken substantially along the plane of the line 8-8 of Fig. 2;

showin a screen of the piping Id-I4 of Fig. 12;

Fig. 15 is a similar view line I5-I5 of Fig. 12;

Fig. 16 is an elevational view ofthe valve memtaken as along the ber used in the casing of- Fig. 12;

Fig. 17 is a sectional view taken as along the line I1i'i of Fig. 16;

Fig. 18 is a face or side elevational view of the cutoff disc employed; 7

Fig. 19 is an edge view of such disc; and

Fig. 20 is a view suggesting the manner in which a cut is made according to the teachings of the present invention.

Referring in detail to the drawings, .the improved machine includes a generally rectangular hollow support I 0 formed with a suitable base portion II and about its upper edge having a vertically extending flange I2. Mounted on the upper side of the support is a housing I3 within which the various cutting operations take place.

Carried by.the support I!) is a shaft I4 on which is mounted one end of a support or carrier I5. Support or carrier I5 is somewhat L-shaped and extends upwardly at the. rear side of the machine and at its upper end carries a shaft I6 on which is mounted an intermediate portion of an arm I! which latter includes a portion I8 extending forwardly at one side of the housing I3 and-also includes portions I9 and 20 extending downwardly and outwardly from the side of shaft I6 opposite that from which portion I8 extends.

In its side wall 2| (see Fig. 4), housing I 3 is provided with an arcuate slot 22 through which extends a shaft 2 mounted in a bearing 24 (see Fig. 1) carried by the forward end of arm portion I8. Secured to said shaft Withinthe housing I3 is the cut-off disc 25. It will be apparent that owing to the pivotal mounting it, the arm l1 may be rocked so as to raise and lower the shaft 23 and thus raise and lower the cut-off disc. Mounted to be shifted with the shaft 23 is a cover or closure plate 26 for the slot 22, the arrangement being such that all portions of'the slot above the shaft, in any P sition of the latter, are always covered by the plate.

The rear lower end portions of the arm portions I9 and 20 are connected by or carry ashaft 21 on which is mounted a plate 28 having an electric motor 29 secured thereto. Plate 28 includes an extension 28a carrying a head-like portion 30 having a slot 3| therein. Such head 30 is located adjacent to an extension; 32 of arm I! and a bolt 33 carried by said extension projects through the slot- 3| and is adapted to be tight ened'to secure the plate 28 and thus the motor 29 in fixed position relative to said arm I I.

Motor 29 includes a shaft 34 carrying pulleys 35 over which are trained belts, not shown, also trained over pulleys 31 on the cut-0E disc shaft of plate 28 is relative to the arm I! and the sup- It so as to cause swinging movement of the cut- -block 39. This hydraulic means includes a cyl..

I from the stock.

38 supported as by strapsfla. 5.

Onloosening of bolts 33 the plate 28may be adjusted about the shaft 21 so as to tighten belts and thereafter the bolt is tightened to hold the plate in its adjusted position. .Such adjustment port l5, but it will be clear that beingmounted by the portions l9 and 20 of the arm and the latter being mounted on the support ii, any movement of the arm and support will resultin movement of the plate 28 and motor 29.

To maintain its driving connection with the shaft 23 and thus with the cut-oi! disc. the motor 29 is at all times moved with the arm ll. Such arm is adapted to be rocked about the shaft of! disc toward and from a piece of work. Within the lower portion of the housing a work-holding means including a V-block 30 and suitable clamps associated with said block and later to be described.

According to the present invention, hydraulic, means are provided for rocking the arm I! in the desired direction at the proper times to carry the cut-off disc to and from work being held in the inder All, the inner or lower end of which is pivotally mounted as at ll on an extension 42 f the oscillatable support I. Within cylinder ll is a piston (not shown) and extending through the upper end of the cylinder is a piston rod 3 attached to said piston and adapted to [be projected and retracted as fluid under pressure is admitted to one end or the other of the cylinder.

The outer end of the pistonrod 43 is pivotally attached as at 44 to an extension 45 of the arm portion It. With this arrangement, as fluid under pressure is admitted to the outer end of cylinder I, the rod 43 is drawn into the cylinder rocking portions I! and 2| hfarm-l1 downwardly and rocking portion I! of said arm upwardly so that the cut-off disc will be carried away from the work.-

Thereafter on fluid under pressure being supplied to the inner end of cylinder ll the piston rod 43 will be forced upwardly rocking the arm II in the opposite direction to swing the cutoff disc toward the work-holder means and to feed such disc through any work in'the holder. The control of the supply of fluidunder pres- .sure to the cylinder 40 will be fully set forth when considering Fig. 11 wherein the piping arrangement for the entire machine is diagrammatically illustrated.

The clamps associated with the V-block 3! are generally designated 46 and 41. Eachclamp is in the form of a rod and clamp 46 extends upwardly into housing It and therein includes a forwardly directed arm 48 having a depending work engaging portion 49. Clamp l1 likewise extends up into the housing If and therein includes a rearwardly directed arm I0 carrying a laterally extended portion the free depending end 52 of which is designed to engage the work. During a cutting operation disc 25 passes between the work engaging portions la and 52 of the clamps-as shown in Fig. 8. Such being the case the large piece of stock 53 is held rigid on the V-block as is the piece 54 being cut I3, there is bracket I! as shown.

At their lower ends within the support ill the clamps are screw threaded or otherwise adjustably connected with'a crossbar 55 which in turn may be screw threaded or otherwise adJustably connected with the upper end portion of a piston 'rod 66 connected with a piston (not shown) within a cylinder 51. Means, later to be described, are provided for selectively applying fluid under pressure to the respective end portions of the cylinder 51. As such fluid is admitted to the lower end of the cylinder; the

clamps l6 and 41 will be raised away from the V-block l9 and as the fluid-is permitted to escape from the lower end portion of the cylinder 15 and isladmitted to the upper end portion thereof the clamps will be drawn down into engagement with the work and securely hold it in the V- block.

Means are provided whereby thecut-oif disc is oscillated. This means so functions that as the hydraulic feed is operating to pass the disc through a piece of work, the disc is being bodily moved or oscillated beck and forth in directions crosswise with respect to the work. At the back of the machine just above the base Ii is a trough a above which is located an electric motor 59, the base I of which is attached to the rear wall of the hollow support III. on a shaft ii, driven by the motor 59, through reduction gearing (not shown) in the gear casing "a, there is'secured a small gear 62. Shaft ll through a coupling 53 also drives the shaft 64 of a pump arranged to supply fluid under pressure to the cylinders Ill and 51 as will later appear. Pump 85 is mounted on any suitable A shaft '1 is mountedin bearings 68 and is locatedbelowand laterally of the motor 59. On

v relation with the gear .9.

Pivotally mounted on the stud I2 is the lower end of a connecting rod or link I4 the upper'end of which enters between a pair. of spaced ears I! rigid with the support I! and the upper end of the link is pivotally connected to said ears as by means of a pin N.- With this construction it will be apparent that when the stud I2 is in eccentric relation to the gear 69, if such gear is being driven, the link ll will transmit'the eccentric motion of the stud to the support I! with the result that the latter will be oscillated about the shaft N. Y

A Shaft is being substantially in vertical alignment with but spaced from the work-holder and the shaft 21, it will be clear that as the support II is oscillated the cut-off disc-will be oscillated or moved back and forth in substantially a straight line. The movement of the support is imparted to the arm I! as the latter is pivoted on the former by shaft I I and the back and forth movement of the cut-off disc will be in the plane of its rotation but substantially at right angles to the movement it receives as the result of the rocking of the arm ll about the shaft It. If stud i2 is adjusted into concentric relation with th gear there will be no 0sciilation of the disc and under other 'circumstances the length of the oscillating movement of rubber sheet I02.

the disc depends on the extent of adjustment of the stud by the screw I3.

Liquid coolant is supplied to the cut-ofl disc whileit is in engagement with a piece of work. To this end a well 11 (see particularlyFig. 8) is formed within the housing I3 and is defined by a. portion of the side ,wall 2| of the housing, a portion of the front wall I8 thereof, a side wall 19 and an inner wall 80, the latter having a veris located a motor 86 by which the pump is driven. From the pump a discharge connection 81 is carried through or around the machine to a pipe 88 which through a nipple 89 discharges into the Well TI.

While in operation pump 83 maintains a circulation of the coolant and as the latter is spilled through the slot M in the front wall of the well (or is carried through said slot by the cut-off disc) it falls onto the wall 90 within the upper portionof the support I and then runs onto and passes through a removable perforated plate 9|, returning to the reservoir 82. If desired screens of suitable mesh may be provided beneath plate 9i. Bushings 92 are located about the clamps 46 and 41 where they pass through a the wall 90 so that all coolant falling onto wall 90 is returned to the reservoir and may not escape into the bed of the machine.

Housing I3 in the upper portion of its side wall 93 (this being the wall directly opposite wall 2|) is, provided with a large opening 93a normally closed by a door 94 hinged at 95 and secured in closed position by catches 96. In its lower portion wall 93 is provided with an opening 9! which while quite large is much smaller than the opening 93a. Opening 91 has its lower portion Vshaped as shown best in Fig. 2 and provides for the insertion of work into the V- block 39. When the cut-off disc is in an upper position opening 93a gives access thereto so that a worn disc may be replaced.

Guide rails 98 are secured to the inner surface of the lower portion of wall 93. The rails are located at opposite sides of the opening 91 and are vertically disposed with their upper ends terminating substantially flush with the lower edge of opening 93a. Screens generally designated 99 are received by the guide rails and each screen comprises an outer metal sheet I00, an-inner metal sheet Plate I00 is provided with an opening I03 while plate I0! is providedwith an opening I04 aligning with but of somewhat greater diameter than opening I03. The rubber sheet is provided with an opening smaller in diameter than opening I03 and about its opening the-rubber sheet is radially slit 'to provide tongues or fingers I05.

A plurality of the screens 99 each having a diiferent size of opening for the passage of work are supplied with each machine. When a certain size of work is to be cutas, for example, the bar 53a screen 99 having an opening of the proper size is placed in the guide rails. Then the work is inserted through the opening in the screen as shown in Fig. 8. As the opening in IOI and an intermediate 4 opening in plate 100, the pushing of the work through the screen results in the fingers I05 of Y the rubber sheet I02 being forced inwardly in a manner to hug the work. Obviously the fingers being flexible and resilient difierent sizes of work, within limits, may be out without changingof screens.

The liquid coolant is kept supplied to they well II in such quantity as to maintain the wen substantially full in spite of the fact that the coolant is constantly gushing through the slot 8I. Further the coolant is being thrown about in the housing I3 by the rapidly rotating disc 25. Screen 99 prevents the escape of the coolant through the opening 91 so that the coolant flows out through the slot 22 and below the lower end of the housing on the wall 92 returning to the reservoir 82'. The relation of the door 94 to the lower edge of the opening 93a is shown in Fig. 9. There it will be noted an angle member I06 on the lower part of the door overlies the upper edge of the lower portion of wall 93 providing additional means to prevent the escape of thecoolant from the housing I3 except through the proper channels.

' Motor 29 and parts adjacent thereto comprise considerable weight which must be moved by the motor 59 operating. through the link" to cause oscillation of the cut-off disc. To partly compensate for this weight a heavy coil spring I0"! is inserted into place bearing at one end against thebase of the machine and at its other end against a plate I08 located at the the support I5. Obviously this spring functions as a counter-balance relieving the load on the motor 59.

Conveniently located at the front of the machine are switches I09, H0 and III controlling the circuits of the motors 29, 59 and 86 respectively. In the forward wall of the support I0 is a relatively large opening II2 normally closed by a plate. I I3 carrying a latch H4 for securing it in place. When this plate is removed access may be had'to the piping leading to and from the cylinders 40 and 51, which piping is located within the hollow support I0 but is not shown in detail.

Pump supplies fluid under pressure to a distributing valve generally designated II5 and mounted at the rear side of the machine as on a bracket H6. The valve includes a casing III and (referring now moreparticularly to Figs.

11 through 17) a valve member II8. Member II8 includes cut-outs or passages II9, I20 and I2I. In the casing I I1 and adapted to be controlled and at various times placed in communication by the cut-cent II9 are ports I22, I23, I24 and I 25. Other ports I26 and I21 are adapted to be placed in communication by the cut-out I20 and yet other ports I28, I29, I30, HI and I32 are controlled by the cut-out 'I2I.

Valve member II8. includes a. stem I33 project ing through the inner end of the casing II! and an opening I34 in the bracket II6and at its,

plate IN is of slightly greater diameter than the.

lower side of port I25.

the fluid into a pipe I38 with-which a pressure guage I39 is connected as by means of a tube I40. The guage is preferably located to be read from the front of the machine. Beyond the guage I39 pipe I38 connects with a port I24 of the valve casing II1.

At some point, in the length of pipe I38 a pressure relief valve MI is connected as by a pipe I42 and such relief valve is adapted to be adjusted from the front of the machine, being connected with a shaft I43 (see Fig. 2) to the forward end of which is attached a hand wheel I44. Valve I being adjusted to the desired pressure, it will by-pass into pipe I45 so that irrespective of the volume delivered by the pump 55 the pressure in the line I38 will remain substantially constant. This pressure is applied to.

the cylinder 40 for-the purpose of raising and ,lowering the cut-ofl disc and for feeding the latter through the work.

' A second relief valve designated I45 is utilized and the same is connected with the discharge from the valve Ill and in-tum has a discharge or return tube I41 to the sump I35. A pipeI48} the pressure in' which is controlled by the relief valve I45, connects pipe- I45 with the port I21 of the distributing valve. If desired a pressure gauge I49 may be connected with pipe I48 to show the pressure therein and when used is preferably located adjacent the guage I39.

A pipe I50 connects port I25 with the lower end of cylinder 40 and intermediate its ends the pipe is connected by a pipe II with the port I29. Port I23 communicates with a pipe' I52 connecting with the upper end of cylinder 40 through an adjustable valve I53 and one way valve 154. A pipe I55 communicates pipe I52 with port I32. A pipe I55 connects port I22 with a pipe I51 communicating at one end with the lower portion of cylinder 51 and at its other end with the port I3I. Somewhat similarly, a pipe I58 connects port I25 with a pipe I59 communicating at one end with the upper end of cylinder 51 and at its other end with the port I28. A

pipe I50 comprising-a return to the sump I35 is connected with the port I30.

2,2e2,o4e

' sump m through a pipe m and discharges Now assuming that a piece of work is in the V-block the shaft I is operated so as to turn the valve member II8 the distance necessary to have cut-out I2I span ports I29, I30 and I3I. This-leaves ports I28 and I32 of the same series closed. It results in cut-out I20 placing ports I25 and I21 in communication andin cut-out II9 being shifted so that while ports I23- and I24 remain in communication, port I22 is cut off from communication with ports I23 and I24 while port I25 remains closed.

With member H8 in this advanced position port I25 being closed there will be no change in conditions insofar as cylinder is concerned. However, fluid under the pressure determined by the setting of the relief valve I will be supplied to the port I25 and then through pipes I58 and I59 to the upper end lof cylinder 51.

This fluid under pressure cannot escape through port I28 since the latter is-closed, but enters the upper end of cylinder 51 to work. on the piston therein.

The fluid already in the lower portion of said cylinder may nowescape through pipe I51, port I3I, cut-out I2I, po'rt I30 to return pipe I50. It cannot escape through pipe I55 since port I22 is now closed. Thus shifting bf the valve member as described results in operation of the piston rod 55 to bring the clamps 45 and 41 down onto the work that may be in the V -block 39. As long as member II8 remains in the described position the clamps willvbe holding the work and the cut-off disc will be held in an elevated position away from the work.

Since the work is being held the cut-off disc may be brought down to perform the cutting operation. Therefore valve member H8 is rotated one step farther. When this adjustment has been made cut-out I2I places ports I30, I3I

and I32 in communication, cut-out I20 maintains ports I25 and I21 in communication and cut-out I I9 places ports I24 and I25 in communication. Since ports I25 and I21 remain in com munication and port I28 remains closed, while With the valve member H8 positioned as in Fig. 11 the cut-off disc 25 is in an upper'position away from the work and the clamps 45 and 41 are likewise in upper positions releasing the work. This is true since the pipe I38 is delivering fluid under pressure to the pipe I52 through port I24, cut-out H9 and port I23 and such fluid under pressure passes freely through the one way valve I54 into the upper portion of the cylinder 40 to forc the piston downwardly therein drawing downwardly on the rod 43 and'rocking the arm I1 about the shaft I5 in a direction to elevate the cut-off disc 25 and maintain itaway from the work-holder; The. fluid cannot escape through the pipe I 55 since the port I32 is closed.

Port I24 is also in communication withthe port I22 so.that fluid under pressure is supplied to the pipe I55 and thence through pipe I51 to the lower end of cylinder 51 forcing the piston therein upwardlyraising the piston rod and thus the work clamps 45 and 41. The fluidcannot escape through the other endof the pipe I51 since the-port I3I is closed. Fluid under pressure is not being supplied to the lower end' of.

port I22 also remains closed and port I3I remains open, the clamps are held down againstthe work, the pressure being in the upper end of cylinder 51. r

Port I24 now being in communication with port I25 fluid unden pressure is supplied through pipe I to the lower end of cylinder 40. This pressure cannot escape through the pipe I5I as port I29'is now closed. Port I32 is open and in communication through port I30 with the return pipe I50. Therefore fluid may escape to the return pipe from the upper-end of cylinder 40.. However such escape is at a predetermined rate since valve I54 opens only. to admit fluid to the upper end of the cylinder and valve. '53 is adjusted to restrict the outflow of fluid from the upper end of the cylinder. As with the described adjustment of the valve member II8 port I23 is closed the fluid escaping from the upper end of cylinder 40 must passthrough pipe I55 and thence through the return pip I50.

Valve I53 restricting the escape of fluid from the upper end of cylinder 40 controls the'rate at which the piston of said cylinder may move the rod 43 outwardly. Thus the rate of downward movement of the cut-off disc is controlled and may be regulated. It is'desirable that the movement of said disc into initialcontact with the work be at a slow rate of speed since if the 5 disc is..suddenly forced against the work it is i I likely that the disc will be broken as it is rotating at a high rate of speed. Under the same condi-. tions if the disc did not break it would deflect out of its proper plane and start the cut in a place not in the true plane of the disc. This would result-in the out being made not at right angles to the axis of the material being cut and wouldproduce cuts not parallel with one another.

With valve I53 properly adjusted there is resistance to the downward movement of the disc andthe latter approaches and engages the work at about the same rate of speed as that at which it mo'vesthrough the work. When th disc engages the work the resistance offered by the cutting operation is .slightly greater than the resistance occasioned by restricting the escape of fluid through the valve I53 and thus ordinarily after the disc engages the work the rate of escape of fluid from the upper end of cylinder 40 becomes unimportant. However, under certain conditions as will later be set forth, the restriction of the rate of escape of fluid from the upper end portion of cylinder 40 continues to be of importance throughout the cutting operation.

After the disc has cut through the work, valve member I I8 is rocked back one step in a counterclockwise direction, closing ports I32 and I25, whereby pressure is no longer applied to the lower side of the piston of cylinder 40. This movethus limit the turning movement of the 'shaft I35. Loose on said shaft at the forward side of the block I59 is a ring-like member I13 having a handle extension I14 normally held spaced" from lever I10 by means of a coil spring I15.

.At-the forward side of the us is disposed on shaft as and b'y-means of a screw I11 said plate is connected with the block I59. Ring-like member I13 has an arcuate' slot I18 through which the screw I11 extends whereby while the plate I n1ust move with the block I59 ment of the member II8 leaves ports I and I21 in communication so that pressure is maintained in the upper portion of cylinder 51 whereby the clamps 45 and 41 are held against the work.

The described shifting of member H9 again places port I 23'in communication with port I24 so that fluid under pressure is again applied to the upper side of the piston of cylinder 40 causing piston rod 43 to be drawn inwardly of the cylinder and resulting in arm I1 being rocked about i the shaft I5 in a direction to carry the disc upwardly away from the work. The next step in the counterclockwise movement of the valve member 8 places it in the position of Fig. 11

maintaining th cut-ofi disc elevated but opening the upper end of cylinder 51 to the return pipe I50 and supplying fluid under pressure to the lower end of such cylinder through pipes I55 and I51 whereby to raise the clamps to released positions.

Mounted in bearings I5I on the front of the machine is a shaft I52 to which is secured a short lever I53 projecting beneath and upon which rests the lower end of a vertically movable rod I54 having a button-like head I55. The arrangement is such that on said rod being depressed it rocks the lever I53 downwardly thereby imparting a rocking movement to the shaft I52. A coil spring I55 on the shaft is anchored at one end toa collar I51 also on the shaft and at its other end bears against. a portion of the machine frame. The tendency of this spring is to turn the shaft I52 in a direction to raise the lever I53 and to return said shaft to a normal position when rocked therefrom as will later appear.

.Rigid with shaft I62 and beneath and substantially in alignment with the forward end of shaft I is a latch member or lever I58. On the end of shaft I35, at the forward side of the machine, there is secured a block I59 having a handle or lever extension I10 adapted to be swung to rock said shaft'and thereby turn the valve member II 8 within the valve casing II1. Adjustable set screws I carried by a bracket l12]li'mit1the movement of the block I59 and and thus the lever I 10, there may be relative movement between the member I 13 and the shaft I35, plate I15 and block I59. In the edge of plate I 15 there is a notch I19 and said edge is cut away to'provide a shoulder I80 and a second notch I8I. Member 13 is provided with a cam shoulder I52 corresponding with the notch I19, with a cam shoulder I83 corresponding with the shoulder I80 and with a cam shoulder I84 corresponding with the notch 'I8I.

When the lever I10 is in the vertical position shown the distributing valve II5.-and the other parts are in the positions shown in Fig. 11. On said lever being swung toward the left in Figs. 1 and 5 a distance suflicient to permit the latch member I58 to enter the notch I19 of plate I15 the valve member H8 is given such movement that while fluid under pressure is still being ad'- mitted to the lower end of cylinder 51 it is also being admitted to the upper end of such cylinder with the result that the work clamps are held in a neutral position. The object of this will later be set forth.

On. lever I10 being moved a distance sufficient ..gage the work. Thereafter lever I10 is swung an additional step in a counter-clockwise direction to-a point where the latch I58 enters the notch I8I. This positions the valve member II8 so that while fluid under pressure continues to be applied to keep the clamps against the work, it is also applied to the under side of the piston of cylinder 40 so as to bring the cut-off disc down and feed it through the work. It will be recalled that owing to the presence of the adjustable valve I53 the disc is not suddenly thrown against the work.

When desired, lever I14 is pressed in the direction of lever I10, compressing the spring I15, and

such movement of the lever I14 results in a turning movement of the ring-like member I13 relative to the plate I15. Such being the case cam shoulder I84 engages the latch I58 and rocks it downwardly against the action ofthe spring I55 releasing said latch from the notch I8I of the plate I15 so that the plate and block I59 and lever I10 may start a. return movement Such return movement will be imparted by the spring I55 just as soon as thelatch is forced from the notch. The return movement is applied to the valve member II8 through the shaft I35 and this adjusts the distributing valve 5 so that the full pressure of the hydraulic medium is applied to the outer end 'of' cylinder 40 resulting in the cut-off disc being raised'from the work. Return movement of the disc; may be and preferably is accomplished by the full hydraulic pressure so that such inovement will be fast.

As a result of the descQbed partial return member I13 a plate movement of lever I18 the latch I88 is now against the shoulder I88 so that the clamps are being held down against the work. To release the clamps lever I14 is pressed toward lever I18 so that cam shoulder I88 presses the latch I88 downwardly beyond the free end of said shoulder I88 permitting spring I85 to again act to move lever I19 toward the vertical position whereby to return-the distributing valve member II8 to the position of Fig. 11.

This results inthe application of fluid under pressure to the lower side of the piston of cylinder 51 so as to raise the work clamps away from the work. Upward movement of the clamps away cut-ofl disc is automatically reversed by the trip that time will be saved if the clamps are stopped just above the work since on the next operation they will have but a short distance to travel to V engage the work.

With this same idea of reducing the time interval between cuts, adjustable stop means is provided for limiting upward movement of the cutof! disc. Such means includes a stop lug I854: (see Fig. 2) secured to the support I5 and an adjustable stop screw I88 carried by the portion 28 of the arm I1. Obviously on the screw I88 engaging the lug I850 further downward swinging movement of the arm portion 28 about shaft I8 is positively prevented. This means that fur- I8 and the cut-oil! .disc carried thereby is also positively prevented.

When a number of pieces of stock of the same or substantially the same diameter are to be cut the screw I88 is adjusted to engage the lug I85a' immediately after the cut-off disc reaches a position slightly above the work to be cut. Therefore after one out has been made, the direction of movement of the disc is reversed (due to manipu- ,lation of the valve II5 as will later be set forth) but the upward movement is checked by engagement of the stop screw with the stop lug. When the next piece is to be cut the disc moves downwardly but a very short distance before engagin the work and there is a considerable savings of time as the disc does not for each cut travel downwardly from the uppermost position to which it may be moved.

The lower end of the vertically slldable rod I84 rests on theupper side of the short lever I88 and is normally held in the position of Figs. 1 and 4 owing to the tendency of the spring I88 to return shaft I82 to a position pressing latch I88 against disc I18. An extension I81 projects forwardly from the front end of arm portion I8 and adjustable through such extension is a screw I88. The screw may include a hand piece I88 for ease in turning the screw to adjust it and the screw is locked in adjusted position by a nut I98 having a. handle-like extension I9I.

Screw I88 is adjusted depending on the work thereby the valve member I I8. Immediately this occurs the direction of movement of the cut-off disc is reversed and the latter is, carried upwardly the distance permitted by adjustment of the top screw I88.

As the plate I18 is thus rotated with the shaft I85 its shoulder I88 is engaged by the latch I88 so that while the direction of movement of the means described, the work clamps 48 and "continue to hold the work in the V-block. Thereafter lever I14 is manually operated to move latch I88 from engagement with shoulder I88 whereupon shaft I85 is further rotated by spring I85 to adjust'the distributing valve and have the clamps moved up away from the work. At this time attention is directed to the fact that by manual return of lever I18 to its normal vertical position the hydraulic means :of the machine may be reversed at will at any point in the cycle of operation of the machine.v

An. adjustable meansis provided for assisting the operator when' positioning work in the holder. Assuming thata piece of work is to be cut, as from a bar, the latter is inserted into the housing l8 through-the screen 99 in such position that, within the housing, the bar is in ther upward swing movement of the arm portion which a piece is to to be cut and the adjustment is such that as the disc.completes a cut the screw is carried into engagement with the head I of the-vertically movable rod I84. Thereafter asthe disc completes 'a cut the screw forces rod I84 downwardly whereby through lever I88 rod or shaft I82 ".is rocked in opposition to the spring I88. This carries latch I88 out of the notch I8I and-the spring I88 then functions to rotate shaft I85 and m attaches to said bar a arm I89 through the free end portion nf'which screw'288 has engages the screw 288 the V-block 89 while an extending portion of the bar may rest on an outer V-block or support I92. The adjustable stop (see Figs. 1, 3 and 4) includes a shaft I98 mounted in suitable bearings and extending through the forward portion of the flange I2 at the upper edge of the machine frame.

By means of a pinchbind I94 a hand lev'er I95 is secured to the projecting end portion of shaft I98 whereby rocking of said lever will result in rotary movement of the shaft. On an intermediate portion of shaft I98 a double pinchbind I98. is secured and receives an end portion of a bar I81 extending forwardly in substantially parallel relation to the hand lever I85.

A pinchbind I98 on the forward end of bar laterally extending there is threaded a stop screw 288. Said screw is in alignment with any work in the V-block '89 so that as the operator pushes the bar, from be cut, through the V-block, the inner end of the bar will engage the forward end of the stop screw. Obviously with this arrangement' the length of the piece cut from the bar by disc 25 will depend on or bedetermined by the adjustment of screw 288.

Assuming that a number of pieces of the samelength are to be cut from a bar and that the been properly adjusted the following procedure may be advantageously employed. The operator pushes the bar forwardly until it and then manipulates lever I18 to cause clamping and cutting of the work. When a piece has been cut fromthe bar (as when the piece 54 has been cut from the bar Y 58) the cut-off disc is raised and the clamps are then raised Then the operator swings the hand lever I85 upwardly raising the bar I91 and the screw 288, The severed piece may then fall from the V-block or be bushed therefrom by shoving the pieceof stock 58 forwardly. Thereafter the operator lowers the lever I95 to bring thescrew 288 back into alignment with the work and the latter is moved forwardly into engagement with from a length of material the pinchbind I96 is.

loosened on the bar I91 and the latter is slipped outwardly to place its inner portion in said pinchbind whereupon the latter is tightened. Thereafter pinchbind I98 with arm I93 and screw 200 are mounted on the outer end of bar I91 in position to have the screw function as a stop for work projecting a considerable distance beyond the V-block. With this arrangement the stop is adjusted to have the machine cut ofl a piece of practically twice the length of the bar I91.

From the foregoing it will be understood that an important feature of the invention resides in the bodily back and forth movement of the cutoff discin the plane of its rotation and while it is being fed through the work; With this arrangement the arc .of contact between the disc and work is kept small and I am enabled to cut pieces of stock of large diameter with a relatively low power consumption. Further as the disc moves back and forth the coolant is admitted to all parts of the cut. Fig. to some extent indicates a cut and there the stock MI is shown as'partly cut through. Excessive back and forth movement of the disc is to be avoided and may in any instance be for a distance less v than the diameter of the piece being out. In

Fig. 20 the center of the disc is moved back and forth the distance between the indicator lines 202 and 203 and the intermediate portion 204 of the cut is substantially straight.

The surfaces 205 and 206 of the out, such surfaces being the ends of the out beyond portion 204, are concave since the surfaces 205 and 206 generally correspond with an'arc of the same length along the periphery of the cut-off disc being used and thus depend on the diameter of the cut-off disc. The showing in Fig. 20 is exaggerated to. suggest the type of out rather than to illustrate a definite cut, the exaggeration being particularly as to the arcs at the ends of the out and being (in the drawings) on a radius smaller than that of any cut-off disc that could be used for cutting the bar 20 I;

In any particular instance the back and forth movement of the disc is adjusted depending on the size of the work to be cut. Assuming that the maximum arc of contact between the disc and work is to be /2 of an inch the throw of the disc will be adjusted accordingly. The maximum contact between the disc and work takes place at the ends of the cutting stroke where a slight portion of the disc in the rear of the axis thereof is in engagement with the work although this.

engagement is of little importance in so far as the removal of material is concerned and may safely be ignored when computing the arc of, contact.

Therefore if the axis of the disc is in a vertical line drawn /2 inch from the edge of the work the disc will engage the work for such distance forwardly of its axis and the engagement between the disc and work in the rear of the axis of the disc will be ignored. Thus if the maximum cutting arc is to be an inch the back and forth movement ofthe disc will be the diameter of the work minus A; inch at each end of thecutting stroke or a total back and forth movement of the diameter of the work minus one inch. With this arrangement or setting of the machine the arc of contact between the disc and the disc and work are purely by way of example and are notcontrolling. Further it will be clear that the configuration of the line at the bottom of the cut will vary according to the diameter of the disc being used' and that the disc is subject to wear. The configuration of the mentioned line also depends on the length of stroke given the disc and such length of stroke is controlled by the setting of the screw II.

Here it is noted that any length of stroke, even a very short stroke, is of advantage in making a cut since the arc of contact between the disc and work will be reduced. As the bottom of the cut between the curved end portions thereof is substantially straight the arc of contact between the disc and work for thisportion of the cut is reduced over the maximum for which the machine may beset and thus it will be clear that at any given time there is but a small arc of contact between the disc and work, the maximum are being at the ends of the cutting strokes.

The are of contact being kept low it will be apparent that the resistance .to the cutting action is never as great as it would be if a section of the periphery of the disc equal to the diameter of the stock was at any one timein engagement with the stock. Thus the back and forth movement of the disc relative to the work is particularly important when cutting stock of large diameter as the resistance to the rotation and downward feed of the disc is kept low.

Adjustment of valve I53 is important. This is true at the beginning and ending of a cut through a round piece of stock as at such timesthe back and forth movement of the disc is usually great enough to have the disc pass beyond the work. Under these or similar circumstances the fluid pressure on the feeding mechanism, if not resisted would force the disc downward to a position at the side of the work. That is, should the disc pass beyond one side of the work the resistancev offered by the work would suddenly cease and the fluid under pressure acting to move the disc would give it a sudden downward movement. Should the disc move beyond the side of a piece of work it will be there but momentarily and cannot drop any appreciable distance due to the fact that downward movement thereof is being resisted according to-the adjustment of the valve I53.

Should the disc drop or be forced down an appreciable distance at either side of the work, then at the start of its return movement the disc would jamb against the work attempting, to make a deep cut therein. When cutting tubing the resistance offered by the setting ofthe valve I53 is important in that the disc during the times it is moving back and forth between the walls of the tubing is supported against any sudden downward movement.

Owing to the fact that the disc is hydraulically fed there is little or no variation in the pressure with which it is held against the work and there is little likelihood of the disc being broken by being jammed against a hard spot in the work as the relief valve of the system will take care of any excessive load. Also with the described except where they may be obtained were the disc manually moved against and through the work. In such latter circumstances there is lacking the element of constant pressure and the operator is likely to force the disc trying to increase this production.

The disc 25is of abrasive material and actually cuts through the work and may be of the construction disclosed in my Patent 2,047,649 of July 24, 1936. Referring to Figs. 18 and 19 the disc is quite thin being generally not over three eighths inch in thickness and generally much less.- Its periphery-is notched asat 201 and it is also provided with openings 208. The openings at opposite sides of the center of the disc are arranged in staggered relation. Therefore as the disc wears down during use, a hole 208 first at one side and then at the-other side of a the center of thedisc will break through provid- 7 ing a notch in the periphery of the disc. Preferably the holes are so related that before a first formed notch is completely obliterated a second hole has been broken through to form a new notch inthe periphery ofthe disc.

As pointed out more fully in the patent above referred to the notches or recesses held the disc clear itself and together with the holes pick up coolant as the disc is rotated with its downwardly moving side in the well 11 and carry such coolant into a out being made.

While. the disc 25 is preferably of abrasive material whereby smooth clean cuts are obtained, for certain jobs. and under .certain conditions other types of discs may be used and I do not the use of abrasive discs specified in the claims. Having thus set forth the nature of vention, what I claim is:

i. In a cut-ofi machine, a work-holder, a thin abrasive cut-oil disc, means for rotating the disc, a pivotally mounted support, an arm pivotally therefore limit myself to holder, and other adjustable means controlling the pressure applied to said clamping means.

4. In a cut-off machine, a-work-holder, clamp-' ing means for securing work in said holder, a cut- Ill on! disc, means mounting the disc and workholder for relative bodily movement to cut the work, hydraulic meansoperable to control said,

clamping means and cause such relative bodily movement of the disc and work-holder, means controlling said hydraulic means whereby after the disc'and workengage the clamping means cannot be released from the work until the disc and work are separated, adjustable means conholder in the housing, a cut nflf disc in the housing, means to rotate said disc, said housing havmy in-. a

mounted on said support, said disc mounted on said arm whereby as the arm is moved about itspivot the disc is swung toward and from the work-holder, and means continuously rocking said support on its pivot whereby as the disc is swung toward the work-holder it is continuously moved back and forth in the plane of its rotation but in directions substantially at right angles to the direction of its swinging movement.

2. In a cut-off machine, a work-holder, a thin abrasive cut-off disc. means for rotating the disc. a pivotally mounted support, an arm pivotally mounted on said support, said disc mounted on said arm whereby as the arm is moved about its pivot the disc is swung toward and from the work-holder, a driven means having connection with said support, and said meansincluding a part adjustable to and from an'eccentric position and adapted when in eccentric position to cause oscillation of the support and thereby movement of relative movement of the disc and work-holder to cut the work, then to cause relative movement of the disc and work-holder to separate the disc from the work and to thereafter operate said clamping means to release'the work, adjustable means controlling'the'pressure used in providing the relative movement between the disc and worktrolling the pressure used in providing relative movement between the disc and work-holder, other adjustable means controlling the pressure and applied to said clamping means.-

5. In a cut-oil maghine'f'a housing, a working a relatively large opening in a side wall for the inserfion of work to. the holder, means for moving said disc toward and from work in the holder, means for supplying the disc with a liquid coolant, guide ways on said housing wall adjacent said opening, a screen in and removable from said guide ways, said screen including a portion having a smaller opening aligning with a portion of the opening in the housing wall, and said screen portion of flexible material to engage work' in-: serted into the housing and prevent the escape of said liquid coolant through such opening in the housing'wall.

6. In a cut-off machine, a work-holder, a cutoff disc, clamps for securing workin the holder,

means for rotating the disc, means mounting the disc for movement toward and from the workholder, hydraulic means for actuating said clamps and for moving the disc toward and from the work-holder, a-manual control for starting said hydraulic means into operation, means whereby on actuation of said hydraulic means said clamps 'are actuated to clamping positions and then the disc is moved to and through the work, trip means for partly reversing the hydraulic 'means when the disc has passed through the work to reverse movement of the disc and carry it out of the work, and said manualmeans then operable to complete the reversing-0f the hydraulic means to move the clamps away from the work.

'7. The combination as in claim 6 wherein said manual control is operable at will during any part of the machine's operation to partly and completely reverse said hydraulic means.

8. In a cutting machine, a thin abrasive cut-off disc, means for rotating the disc, means mounting the disc for movement'to carry it through a piece to be cut, hydraulic means for effecting such movement of the disc and including a cylinder and piston construction of which one is anchored .and the other is connected with said mountin means, means for supplying fluid to opposite sides of the piston for moving the disc toward and from the work, and means restricting the flowof fluid from one side of the piston while fluid is being supplied to the other side thereof to move the disc toward the work whereby movement of the disc toward the work is resisted but in a lesser degree than that occasioned by-movement of the disc through the work in an actual cutting opera-, ion.

9. In a cutting machine, a cuttingdisc, means for rotatingthe disc, means mounting the disc for movementto carry it through a piece to be cut, hydraulic means for effecting such movement or moving the disc toward and from the work. means for imparting a back and forth bodily movement to the disc in directions substantially at right angles to the directions of movements toward and from the work, and means restricting the flow of fluid from one side of the piston while the fluid is being supplied to the other side thereof to move the disc in the direction of the work whereby such movement of the disc outside the work is resisted but in a lesser degree than that occasioned by the actual cutting operation. v

10. In a cutting machine, a housing, a workholder in the housing, a cutting disc in the housing, means to rotate the disc, said housing having a relatively large opening in a side wall for the insertion of work to the holder, means operable to move the disc toward and from work in the holder, means for supplying liquid coolant to the disc, a. removable screen over said opening, said screen including a portion having a smaller open-- ing aligning with a portion of the opening in the housing wall, and said screen portion of flexible material to engage work inserted into the housing and prevent the escape of said coolant through the opening in the housing wall.

- 11. In a cutting machine, a housing, a workholder in the housing, a cutting disc inthe hous ing, means to rotate the disc, said housing having a relatively large opening in a side wall for the insertion of work to the holder, means operable to move the disc toward holder, means for supplying liquid coolant to the disc, a removable screen over said housing, said screen comprising a laminated structure including a pair of sheets having a smaller opening aligning with a portion of the opening in the housing wall, and one of said sheets or flexible material to engage work inserted into the housing and prevent the escape of said coolant through such opening in the housing wall.

, HARRY G. ROBINSON.

and from work in the 

